Gun recoil spring assembly



April 1, 1969 F. A. PACHMAYR E AL GUN RECOIL SPRING ASSEMBLY Sheet of 3 Original Filed Dec.

G 2? y 7 vLR E \s mum u m m A .N T 6 P B1 H 82 Aw Kn a U l 2 I71 7 5 w April 1, 1969 PACHMAYR ET AL 3,435,728

. GUN RECOIL SPRING ASSEMBLY Griginal Filed Dec. 29. 1966 Sheet 2 of 3 m o' La i 59 av g l I NVENTORS FQAN/z H. PACHMA v Fan/42D .3 M/LL F. A. PACHMAYR E L Apiil 1, 1969 GUNRECOIL SPRING ASSEMBLY Original Filed D80. 29, 1966 Shee t 3 of INVENTORS Fan/v1: .5. PAcu/vm Y? EDWARD B. M BY United States Patent 3,435,728 GUN RECOIL SPRING ASSEMBLY Frank A. Pachmayr and Edward B. Miller, Los Angeles, Calif., assignors to Pachmayr Gun Works, Inc., Los Angeles, Calif, a corporation of California Original application Dec. 29, 1966, Ser. No. 605,825. Divided and this application May 31, 1968, Ser. No. 733,367

Int. Cl. F41c 21/18; F41d /02 US. Cl. 89199 11 Claims ABSTRACT OF THE DISCLOSURE A gun having a slide which recoils in a front to rear direction relative to the receiver of the gun, and having a recoil spring resisting rearward movement of the slide, and a plug urged forwardly by the spring, with forward forces being transmitted from the plug to the slide by a retaining plate which is movable upwardly within a guideway in the slide to an active position, and is withdrawable downwardly from the slide to free the plug and spring for removal. The recoil spring is desirably so constructed that, in its full recoil position, the successive turns of the spring are in direct metal to metal contact, to assist coacting stop shoulders on the slide and receiver in positively limiting the recoiling motion.

Cross references to related applications This application is a division of our co-pending application Ser. No. 605,825, filed Dec. 29, 1966, entitled Accurized Pistol Structure. Another division of the same case is being filed concurrently herewith, as application Ser. No. 733,142, filed May 29, 1968, entitled Gun Having Movably Mounted Barrel.

Background of the invention This invention relates to improvements in the construction of guns, particularly in guns having an action of a type utilized in certain automatic pistols, with the improvements being designed for the purpose of increasing the accuracy of such guns.

The guns with which the present invention is concerned are of a type having a slide which reciprocates rearwardly and then forwardly relative to the receiver of the gun during recoil, and relative to the barrel. This recoiling motion may be utilized for effecting removal of a fired cartridge case from the gun, and advancement of a next successive cartridge into firing position.

Guns of the above discussed type as conventionally manufactured are very inaccurate by reason of the ineffectiveness with which the slide, barrel, and receiver are held in alignment with one another, and by reason of the looseness normally encountered in the connections between these various parts, as a result of which there is no reliably and precisely maintained relationship between the gun barrel and the sights of the gun. Consequently, even though a marksman may aim the gun perfectly insofar as sights are concerned, and may be completely consistent in such aiming, slight changes in the positioning of the barrel relative to the sights after different recoiling operations can introduce errors into the firing of the gun which are completely beyond the control of the user.

Some of this inaccuracy has been caused by the ineffective manner in which the barrel of the gun has been located relative to the recoiling slide. More particularly, the forward end of the barrel is usually retained within a tubular bushing element, and is relatively loose therein to allow slight downward swinging movement of the breech end of the barrel upon firing, but with the result that the barrel is not accurately located by the bushing.

Patented Apr. 1, 1969 Further, the bushing is, in a conventional gun of the type being discussed, required to serve a secondary function of retaining in the gun a recoil spring, and a plug by which forward forces are transmitted from the spring to the slide. The forces exerted against the bushing by the spring may result in improper positioning of the bushing; and the necessity for transmission of these forces through the bushing renders it difficult to design the bushing for precise positioning of the barrel therein.

Summary of the invention In our previously filed co-pending application Ser. No. 605,825, we have disclosed a new type of bushing arrangement which very precisely and accurately locates and guides the forward end of the barrel in a gun of the above discussed type, to completely eliminate any possibility of looseness between the bushing and barrel. The present application covers a unique type of retaining element, which may be used in conjunction with the bushing of that co-pending application, or which may be used in conjunction with other improved bushing structures, and which transmits forces from the recoil spring to the slide without affecting the optimum positioning of the barrel by the bushing. More specifically, the retaining element is mounted to the slide for bodily sliding movement essentially transversely of the barrel, and between an active position in which the element transmits forward forces from the spring to the slide, and an inactive position in which the spring is free for removal from the gun. The retaining element may engage the forward end of the usual recoil spring plug, and desirably contains an opening into which a forward projection on the plug extends when the parts are in assembled relation. The parts may then be easily disassembled by merely pushing the plug rearwardly out of the mentioned opening, to free the retaining element for sliding movement transversely of the barrel and spring and out of the guideway within which the retaining element is slidably received.

Another feature of the invention has to do with the formation of the spring and other parts in a manner such that, in the full recoil position of the slide, the motion of the slide is limited by direct metal to metal contact between successive turns of the spring, which in effect converts the spring to a rigid essentially integral stop structure supplementing the effect of other stop shoulders in the gun.

Brief description of the drawing The above and other features and objects of the invention will be better understood from the following detailed description of the typical embodiments illustrated in the accompanying drawing, in which:

FIG. 1 is a side view of an automatic pistol constructed in accordance with the invention;

FIG. 2 is a greatly enlarged side view of the pistol, with some elements partially broken away;

FIG. 3 shows the gun in recoil position;

FIGS. 4, 5 and 6 are views taken on lines 44, 5-5 and 6-6 respectively of FIG. 2;

FIG. 7 is a fragmentary horizontal section taken primarily on line 77 of FIG. 3;

FIGS. 8 and 9 are vertical sections taken on lines 8-8 and 9-9 respectively of FIG. 2;

FIG. 10 is an enlarged section on line 1010 of FIG. 8;

FIG. 11 is a perspective view of the barrel mounting link;

FIG. 12 is a fragmentary side view of a variational type of front bushing structure;

FIGS. 13 and 14 are views taken on lines 13-13 and 1414 respectively of FIG. 12, and partially broken away;

3 FIG. 15 is a fragmentary vertical section taken on line 1515 of FIG. 13; and

FIG. 16 is a plan view of the FIG. 12 bushing.

Description of the preferred embodiments Referring first to FIG. 1, we have shown at a gun of a well known conventional type to which the features of the present invention may be applied, and in connection with which these features will be discussed..This pistol includes a receiver or main body part ll, having'a handle 12 and a trigger 13. A magazine represented at 14 is contained within the handle 12, and holds a series of shells which are sequentially fed to firing position and then automatically ejected from the gun upon successive actuations of the trigger. To the upper side of receiver 11, there is movably mounted a slide 15, which is mounted slidably to the receiver forrecoiling movement between the battery or firing position of FIGS. 1 and 2, and the full recoil position of FIG. 3, and which is then returned by a spring 16 (FIG. 2) 'to the FIGS. 1 and 2 position. This rearward and then forward reciprocating movement of the slide is along the front to rear axis designated 17in FIG. 2.

Contained within the slide, there is a barrel 18, which is approximately aligned with the slide, but whose axis 19 is actually inclined slightly upwardly and rearwardly in the FIG. 2 battery position. During recoil, the breech end of the barrel 18 swings slightly downwardly to the FIG. 3 position, with the movement and positioning of the breech end of the barrel being controlled by a link assembly designated generally by the number 20, and with the forward or muzzle end of the barrel being located by a bushing 21.

The manner in which slide is mounted and guided for its recoiling movement is brought out best in FIG. 6, which illustrates that the receiver has two upper edges 22 forming oppositely directed parallel flanges 23 extending in a front to rear direction, and coacting with inwardly directed parallel flanges 24 formed on the lower edges of slide 15, in a relation such that each of the flanges 23 and 24 is received within a recess or guideway in the other part, to guide the slide for its desired front to rear recoil ing movement, while precluding substantial movement in any other direction.

The barrel 18 of course forms essentially a tube, having an inner substantially cylindrical bore or passage 25 centered about axis 19 and open at its rear end to receive a cartridge, and open at its forward end for discharge of the projectile. Externally, barrel 18 has a cylindrical surface 26 extending rearwardly from its forward end 27 to a location 28. Beyond this location, the barrel may enlarge slightly externally, to form a pair of upwardly projecting semi-circular ribs 29 receivable within mating recesses 30 formed in the interior of slide 15. As will be apparent from FIGS. 2, 5 and 6, the slide extends about the upper side of the barrel, and extends downwardly at its opposite sides, and has an enlargement 31 extending downwardly from the forward end of the slide for coacmay carry an essentially annular enlarged diameter flange 38, which may be cut away arcuately at its underside, at 39 (FIG. 4), and which carries at its upper side a forward sight 40 for aiming the gun. This forward sight coacts with the usual rear sight 41, which may be carried by the rear portion of slide 15, to define an aiming or sighting. line 42 which is parallel to or essentially parallel to axis 19 of the barrel and bushing.

Bushing 21 is connected to slide 15 for relative pivotal movement about an axis 43 disposed transversely of the barrel and bushing and their longitudinal axis 19 (FIGS. 2 and 5). For this purpose, I provide two pivot or trunnion elements 44 (FIG. 5), each of which may take the form of a screw having threads 45 centered about axis 43 and connected into threads46 also centered about that axis and formed in the slide. Each of these screws may have an enlarged head 47 which is tightenable against the vertical outer surface 48 of the slide, and containing a screwdriver slot. Inwardly beyond its threads 45, each screw may have an externally cylindrical reduced diameter portion 49, centered about axis 43, and received within a correspondingly dimensioned cylindrical opening 50 formed in one side of bushing 21, to mount the bushing for'the desired pivotal movement about axis 43. The fit between surfaces 49 and 50 should be close, to prevent any relative motion between the bushing and elements 44, so that the bushing can only move pivotally. As will be apparent from FIGS. 2 and 5, the outer spherical surface 37 of the bushing is centered about a point 51 located at the intersection of axes 19 and 43, and is a diameter corresponding to the diameter of an engaged inner cylindrical surface 52 formed in the slide, so that the interengagement of surfaces 37 and 52 coacts with trunnion elements 45 in preventing upward, downward or lateral movement of the bushing relative to the slide.

At its breech end, barrel 18 has a downwardly projecting connector portion 53, which is integral with the rest of the barrel and may form two laterally spaced depending lugs 54 (see FIG. 6), each having the side view configuration illustrated in FIG. 2. Lugs 54 are pivotally connected by a pin 55 to a link 56, Which forms with the other related parts the link assembly heretofore referred to generally by the numeral 20, for controlling the movement of the breech portion of the barrel. Link 56 is in turn pivotally connected to a receiver 11 by a pin 57 (FIGS. 2 and 6), which extends through and is located by two cylindrical passages 58 formed in opposite sides of the receiver. Pin 57 has an enlarged head 59 at one of its ends, and adjacent the head extends through an opening within the usual slide stop 60, which coacts with the slide to hold it in open or recoil position under certain operating conditions. As will be understood, slide stop 60 is in most guns of the present type integral with pin 57, but in accordance tion with recoil spring 16. An opening 32 in the upper side of the slide allows for ejection of the fired cartridge case in the recoil position of FIG. 3.

About the forward cylindrical surface 26 of barrel 18, there is disposed the previously mentioned bushing 21 (FIG. 2), which is tubular and has an inner straight cylindrical surface 34 of a diameter corresponding substantially to the diameter of outer surface 26 of the barrel, and a close enough fit on that surface to accurately locate the barrel relative to the bushing, while still allowing free rearward sliding movement of the bushing relative to and about the barrel to the position of FIG. 3. Externally, the bushing may have outer cylindrical surfaces 35 and 36 centered about the axis 19 of the bushing and barrel, with an enlarged diameter spherically curved outer surface 37 located between surfaces 35 and- 36, and centered about a point on axis 19. At its forward end, the bushing with the teachings of Patent No. 3,207,037, I prefer to form it separately from the pin as shown. At the second side of the receiver, the pin 57 may be held in installed position by means of a retaining snap ring 61, which may be resilient and extend more than half way about pin 57, and be received within an annular groove 62 to retain the pin against removal.

Pins 55 and 57 are disposed about axes which extend transversely of the recoiling axis 17 of the slide, and transversely of axis 19 of the barrel and bushing, though not actually intersecting these axes. Link 56 has an upper portion 63 which extends upwardly between, and is a close fit between, the two depending lugs 54 of the barrel, with pin 55 extending through mating apertures in lugs 54 and end portion 63 of the link to interconnect these parts for the desired relative pivotal movement between the positions of FIGS. 2 and 3. Beneath its portion 63, link 56 may have a widened portion 64. As best seen in FIG. 6, this portion 64 of the link, and the two lugs 54 on the barrel, have parallel planar surfaces at their opposite sides which are spaced in correspondence with the spacing 'of inner vertical planar surfaces 66 defining the opposite sides of a recess in the receiver within which the link is contained, so that the opposite sides of the link and of lugs 54 simultaneously engage both of the surfaces 66, to effectively confine link 56 and lugs 54 against any lateral movement, longitudinally of pins 55 and 57. Surfaces 66 in the receiver and the engaged surfaces of the link and barrel lugs are of course disposed transversely of pins 55 and 57, and therefore lie in planes which are essentially parallel to axes 17 and 19.

At its underside, and forwardly of the axis of pin 57, link 56 has a planar undersurface 67, which in the battery position of FIG. 2 extends directly horizontally and abuts downwardly against a horizontal bottom wall surface 68 formed in the receiver. Thus, this interengagement of surfaces 67 and 68 acts to positively limit the upward and forward movement of the barrel in the FIG. 2 position. In the FIG. 3 position, two rearwardly facing vertical planar surfaces 69 formed on the back sides of lugs 54 engage a vertical planar surface 70 formed in the receiver and disposed perpendicular to axis 17, to prevent any further rearward and downward movement of the barrel. It is also noted that, in the FIG. 2 position of the barrel, pin 55 is desirably located approximately directly above pin 57 (preferably slightly forwardly of a position of exact vertical alignment of the pins). Because the pins are in this approximate vertical alignment, any slight forward or rearward shift which may occur for any reason in the firing position of the barrel can not alter substantially the vertical position of the breech end of the barrel, or the position of barrel axis 19.

The forward end of helical recoil spring 16 is received within and bears forwardly against a plug 71, which contains a cylindrical passage 72, within which the spring is a fairly close fit. The forward end of the plug forms a transverse wall 73 against which the spring bears, and which has a reduced diameter externally cylindrical portion 74 and a forward annular transverse surface 75. Except at the location of this forward portion 74, the plug may have an increased diameter external surface 76 which is slidably received and located within a cylindrical passage 77 formed in the downwardly projecting forward portion 31 of the slide. The plug is retained against forward movement relative to the slide, to transmit forward forces of the spring to the slide, by means of a retaining element 78, which is slidably received within a guideway 79 formed in portion 31 of the slide, and extending vertically or transversely of axis 17. As will be apparent from FIGS. 2 and 8, element 78 may take the form essentially of a fiat plate, which bridges across the passage 77 in the lower portion of the slide, with the guideway 79 in that portion of the slide forming an opening extending across the bottom of the slide at 80, and forming two parallel internal guideway grooves 81 extending upwardly within the opposite side portions 82 of the slide portion 31. The peripheral shape of retaining element 78 is brought out best in FIG. 8, which illustrates the part as having a lower externally semi-circular portion 178 which is received within opening 80 and has its outer semi-circular surface flush with the outer surface of slide portion 31. Above portion 178, element 78 has two parallel vertical edges 278 which are slidably received and guided within grooves 81. Element 78 also has an essentially central opening 83 dimensioned in correspondence with forward reduced diameter portion 74 of plug 71, to receive that portion of the plug in interfitting relation in a manner locking element 78 against downward removal from the slide.

The rear end of the compression spring 16 is received about a spring guide 84, having a flange 85 at its rear end against which the spring exerts rearward force. This flange 85 in turn bears against a forwardly facing shoulder 86 for-med in and by the receiver, with a portion 87 of the guide projecting rearwardly beyond that shoulder. This portion 87 of the guide is in conventional guns of this general type annular, but in accordance with the present invention is specifically formed to avoid interference with the forwardmost portion of link 56, and for this purpose portion 87 of the guide 84 is milled to form a vertically extending slot or cutaway as shown at 88 in FIGS. 7 and 9. The forward portion of link 56 is reduced somewhat in width at 89 (FIGS. 2, 7 and 11), so that this slightly reduced width portion of the link may move upwardly and downwardly within the slot or cutaway area 88 in guide 84 as the link pivots between the positions of FIGS. 2 and 3.

The rearward recoiling movement of slide 15 is in most guns of the present type limited by engagement of the thickened essentially annular portion 90 (FIG. 3) of the slide with the flange of spring guide 84. To supplement this motion limiting action, we so dimension the various parts and particularly spring 16 that, in the fully recoiled position of FIG. 3, the successive turns of the spring are all in direct essentially annular engagement with one another, so that there is direct metal to metal contact (continuously throughout 360 circular degrees) between all of the various successive turns of the spring, and between the end turns and the parts engaged thereby, to thus in effect form through the spring a rigid metal connection between surface 73 at the forward end of plug 71 and the flange 85 of spring guide 84, to in this way coact with the previously mentioned engagement between portion of the guide and flange 85 in positively limiting the recoiling motion.

To now describe a cycle of operation of the pistol shown in FIGS. 1 to 11, assume that the gun is in the battery condition of FIG. 2, and that a loaded magazine has been inserted into the handle of the gun, and that one round has been properly positioned in the breech end of the barrel. With the gun in this condition, the user may aim the gun by means of sights 40 and 41, and then pull the trigger so that hammer 91 causes firing pin 192 to fire the shell which is in the barrel. The gases of combustion produced in the barrel act through the cartridge case to force slide 15 rearwardly relative to the receiver and barrel to the FIG. 3 recoiled position. During the initial portion of this slide movement, the recoil forces also cause the breech end of the barrel to swing rearwardly and downwardly to its FIG. 3 position, about axis 43, with this motion of the barrel being limited by engagement of lugs 54 with receiver shoulder 70. The rearward motion of the slide causes ejection of the fired cartridge case, and enables a next successive round to move into firing position in the barrel, following which spring 16 returns the slide forwardly to its FIG. 2 position, with the forwardly facing vertical shoulder surface 92 of the slide first shifting the cartridge forwardly into the barrel, and then engaging the barrel itself during the final portion of the slide movement to force the barrel forwardly and upwardly from its FIG. 3 position back to its FIG. 2 position, in preparation for the next successive firing operation.

The trunnion mounting of the muzzle end of the barrel very eflectively locates that portion of the barrel in precisely predetermined position relative to the slide, when the parts are in the battery condition of FIG. 2, and in spite of the limited pivotal movement permitted between these various parts during recoil. Also, the link 56 and its related parts effectively locate the breech end of the slide, preventing any lateral movement thereof, and precisely predetermining the height of the breech end throughout its complete cycle and in its final position. This final battery position of FIG. 2 is rendered very accurate by limiting the returning movement of the barrel by engagement of the previously discussed shoulder or surface 67 on line 56 with the upwardly facing surface 68 in the receiver. In thi connection, it is noted that there is preferably no motion halting interengagement between the line ad lugs 54 at the location designated 92' in FIG. 2, or between any other surfaces except at shoulder 67, so that the engagement of this shoulder on link 56 with surface 68 may desirably function alone to determine the forwardmost position of the barrel.

When it is desired to dismantle the gun, or for other reasons have access to spring 16, a person may merely press the reduced diameter forward portion 95 of plug 71 rearwardly out of the opening 83 of retaining element 78, and far enough to enable the retaining element to be slid downwardly, transversely of the axis 96 of the spring, and out of the guideway 79, so that the plug and spring may be withdrawn forwardly from the slide. Bushing 21 may be removed by unscrewing the retaining trunnion elements 44, and the other parts of the gun may be dismantled in conventional manner.

FIGS. 12 through 16 show a variational type of bushing 97 which may be substituted for the bushing 21 of FIGS. 1 to 11, and which functions as does bushing 21 to accurately locate the forward end of a gun barrel 18a and mount that barrel for only predetermined limited pivotal movement relative to a gun slide 15a about a transverse axis 43:: corresponding to axis 43 of FIG. 4. Except with respect to the structure at bushing 97, and the other features discussed hereinbelow, the gun of FIGS. 12 through 16 may be considered as essentially identical with that of the first form of the invention.

Bushing 97 of FIGS. 12 through 16 is desirably stamped from a single piece of sheet material, preferably high quality sheet steel heat treated after stamping to spring temper. This sheet material is stamped to provide a vertically extending front wall portion 98 of the bushing, which extends vertically in front of and in spaced relation to the plane of vertical end surface 99 of slide 15a. At the center of this vertical wall 98, the sheet material is shaped to provide a rearwardly projecting tubular portion 100 of the bushing, which portion has an inner cylindrical surface 101 corresponding substantially in diameter to the outer cylindrical surface of barrel 18a, to guide the bushing for axial sliding movement along the barrel. This tubular portion 100 of the bushing extends rearwardly into the interior of the slide, as seen clearly in FIG. 15, and is spaced radially from the slide at 102 to enable the desired limited pivotal movement of the bushing with the barrel.

At its opposite sides, the sheet material of bushing 97 forms two rearwardly projecting parallel mounting arms 103, which may be identical and lie in parallel vertical planes, and which abut laterally against the vertical parallel opposite side surfaces 104 formed on slide 15a. These side surfaces 104, and the arms 103, lie in vertical planes which are parallel to the vertical central plane 105 of the gun extending through axis 106 of the barrel. As will be understood, the abutting engagement of the inner vertical planar surfaces 106 of arms 103 with slide surfaces 104 effectively locates the bushing 97 against lateral movement relative to the slide.

Arms 103 contain two aligned openings 107 (FIG. 14) within which there are received two pivot screws 108 having externally threaded shanks screwed into internally threaded passages 109 formed in the opposite side walls 110 of the slide. Screws 108, passages 109, and openings 107 are all centered about transverse axis 43a, so that the screws guide arms 103 and the rest of bushing 97 for the desired pivotal movement about that axis. For this purpose, the head 111 of each of the screws 108 has an outer cylindrical surface 112 centered about axis 43a, which surface engages in closely fitting bearing relation a correspondingly cylindrical surface 112 of the opening 107 in the associated arm 103, with surface 112 also being centered about axis 43a. The forward sight 40 of the gun shown in FIGS. 12 to 15 is typically illustrated as mounted to the forward end of the slide, in essentially conventional manner.

In using the gun of FIGS. 12 to 16, the operation is substantially identical with that previously discussed in connection with FIGS. 1 through 11, except for the difference in structure of the bushing 97. As in the first form of the invention, this bushing pivots around transverse axis 43a, as the bushing and slide recoil rearwardly relative to barrel 18a, with this slight pivotal movement of the bushing being suflicient to enable the desired slight rearward and downward swinging movement of the breech end of the barrel during recoil. The spacing of bushing 97 from the forward end surface 99 of the slide and from the inner surfaces of the slide at 102 (FIG. 15) is sufiicient to avoid any interference with the desired pivotal movement of the bushing. As in the first form of the invention, the barrel is very effectively located by the bushing, and very accurately and precisely maintained in a desired set position relative to the barrel in the battery position of the slide, to avoid any loss of aiming characteristics of the gun such a occurs in conventional fire arms of this same general type in which the forward end of the barrel is only loosely located.

During assembly of the arrangement of FIGS. 12 to 16, the bushing 97 may be placed in its illustrated position about the slide prior to the attachment of screws 108 to the slide, and the screws may then be very easily inserted through openings 107 in arms 103 and screwed into the slide. Alternatively, the parts may be assembled in a reverse manner in view of the resilience given to arms 103 by the previously mentioned heat treating of the bushing to spring temper. That is, screws 108 may first be connected to the slide, and the bushing then be applied by spreading its arms 103 sufficiently apart to move them past the screws until openings 107 align with the screws, so that the arms may then move inwardly by their own resilience against the opposite sides of the slide and into interfitting pivotal engagement with the screws.

We claim:

1. A gun comprising a receiver, a barrel, a slide mounted for front to rear recoiling movement relative to the receiver, a spring yieldingly resisting said recoiling movement of the slide and yieldingly urging the slide forwardly, an element for retaining said spring in compressed condition and transmitting forward forces from the spring to said slide, and means guiding said element for bodily sliding movement relative to said slide in a direction essentially transversely of said barrel and between an active position in which said element transmits said forward forces from the spring to the slide and an inactive position releasing the spring from compression.

2. A gun as recited in claim 1, including a plug engaging a forward end of said spring and urged forwardly thereby and having a forward end engaging said element and held against forward movement thereby in said active position of said element.

3. A gun as recited in claim 2, in which said means guiding said element for sliding movement include means forming an essentially vertical guideway in said slide beneath the barrel into which said element is insertible upwardly toward the barrel to said active position, said element having opposite side edges receivable in said guideway and having an aperture between said edges receiving said forward end of said plug.

4. A gun as recited in claim 1, in which said means include a guideway in the slide beneath the barrel, guiding said element for upward movement toward the barrel and to said active position and downward movement to said inactive position.

5. A gun as recited in claim 1, in which said means include a guideway in the slide beneath the barrel, guiding said element for upward movement toward the barrel and to said active position and downward movement to said inactive position, said slide having an undersurface which curves upwardly at opposite sides thereof, and said element having a bottom edge which curves upwardly in essential correspondence with said undersurface of the slide and is generally flush therewith in said active position of the element.

6. A gun as recited in claim 1, including a plug urged forwardly by said spring and having a projection extending forwardly at its forward end, said plug having a forwardly facing shoulder surface disposed about said projection, said element containing an opening receiving said projection on said plug to lock the element against removal, and said element having a rearwardly facing surface about said opening engageable with said shoulder surface on the plug to retain the plug and spring against forward movement in said active position of said element.

7. A gun as recited in claim 1, in which said means include a guideway in the slide beneath the barrel, guiding said element for upward movement toward the barrel and to said active position and downward movement to said inactive position, said gun including a plug urged forwardly by said spring and having a main essentially tubular portion disposed about the spring, said plug having a transverse wall at its forward end against which the spring exerts forward force, said plug having a short circular projection of a diameter less than the external diameter of said main tubular portion and projecting forwardly at the front of the plug, said plug having a forwardly facin annular shoulder surface disposed about said projection, said element being a vertical plate containing a circular opening receiving said projection on the plug to lock the element against downward removal from said guideway, and said element having a rearwardly facing vertical surface about said opening engageable with said shoulder surface on the plug to retain the plug and spring against forward movement in said active position of the element.

8. A gun as recited in claim 1, including a plug engaging a forward end of said spring and urged forwardly thereby and having a forward end engaging said element and held against forward movement thereby in said active position of said element, said slide having a bottom essentially semi-cylindrically curved wall extending about the underside of said spring and plug, and having spaced opposite side walls continuing upwardly from opposite sides of said semi-cylindrically curved bottom wall, said means guiding the element including an essentially semi-circular slot formed in said bottom curved wall and through which said element is insertible upwardly to active posi tion, and including two opposed essentially vertical guideway grooves formed in the inner surfaces of said side walls and lying in essentially the same vertical plane as said slot, said element being an essentially vertical plate having a lower portion received in said slot in said active position and curved in essential correspondence with the undersurface of said curved bottom wall of the slide, said plate having an upper portion of reduced width received and slidably guided in said grooves, and said plate having upwardly facing shoulders at the juncture of said lower and upper portions of the plate and engageable upwardly with shoulders on the slide at the upper ends of said slot to limit upward movement of the plate.

9. A gun comprising a receiver, a barrel, a slide mounted for front to rear recoiling movement relative to the receiver, a coil spring extending essentially parallel to the barrel and yieldingly resisting said recoiling movement of the slide, said spring having a forward end exerting force forwardly against said slide and a rear end exerting force rearwardly against the receiver, said slide being movable rearwardly far enough to compress successive turns of said spring into direct engagement with one another so that the spring turns provide a direct metal to metal stop limiting said recoiling movement.

10. A gun as recited in claim 9, including means forming stop shoulders carried by the receiver and slide interengageable to limit said recoiling movement in the position in which said successive spring turns are in engagement with one another to coact with the spring in halting recoiling movement.

11. A gun as recited in claim 9, including a spring guide at the rear of said spring having a portion projecting forwardly into the spring and having a generally transverse increased dimension flange against which the spring exerts force rearwardly, said flange being engagea'ble with the receiver to transmit rearward forces from the spring to the receiver, said slide having a portion projecting rearwardly at the underside of the spring and engageable with said flange on the spring guide to limit said recoiling movement in the position in which said successive spring turns are in engagement with one another, to coact with the spring in halting recoiling movement.

References Cited UNITED STATES PATENTS 984,519 2/1911 Browning 89163 X BENJAMIN A. BORCHELT, Primary Examiner.

STEPHEN C. BENTLEY, Assistant Examiner. 

